Examples of a conventional technique for managing the history of an electronic component on a printed circuit board using an RFID tag include one disclosed in JP-A-2007-66989 (Patent Document 1). Patent Document 1 discloses management of the history of an electronic component by mounting an RFID tag having an antenna and an IC chip within a printed circuit board. More specifically, there is disclosed a printed circuit board including at least one conductor layer and having an RFID tag placed therein or thereon which is configured such that the upper and lower surfaces of the RFID tag have no wiring pattern made of the conductor layer. There is also disclosed a printed circuit board including at least one conductor layer and having an RFID tag which is structured such that a through hole having the same vertical and horizontal dimensions as those of the RFID tag is formed in a part of the printed circuit board without any wiring pattern made of the conductor layer and such that the RFID tag is embedded in the through hole.
WO 97/09641 (Patent Document 2) discloses a formation of an antenna of an RFID tag on a printed circuit board (PCB) or at a metal layer in a PCB. The RFID tag includes a semiconductor circuit contained in an electronic package, and an RF antenna unit of the tag is formed in or on the PCB. The electronic package is disclosed to be connected to the antenna via pads on the PCB.
In the technique disclosed in Patent Document 1, a common IC tag, i.e., an antenna having an IC chip mounted thereon is affixed to a printed circuit board. For this reason, printed wiring cannot be provided in a region on the printed circuit board where the antenna is arranged in Patent Document 1.
In the technique disclosed in Patent Document 2, a printed circuit board has an antenna formed thereon and an IC chip mounted thereon. To this end, a multilayer board is employed as the printed circuit board, and the antenna is formed using layers (see FIG. 2 in Patent Document 2). An area larger than that of the IC chip is required to achieve this configuration. In other words, since an antenna is present on a printed circuit board in each of Patent Documents 1 and 2, the component mounting density of the printed circuit board decreases.
The capacitance between an antenna and printed patterns (wiring patterns) peripheral to an RFID tag changes depending on the layout of the printed patterns. This changes the tuning frequency of the antenna and may cause the communication distance of the RFID tag to fluctuate. Accordingly, antenna design needs to consider and include matching of the impedances of an IC chip and an antenna and further needs to be done with peripheral patterns in mind. Printed circuit board-based design is thus required, and the number of man-hours required for design increases.
A case where replacement of lots of mounted components has occurred when a large number of electronic boards are continuously manufactured, i.e., production of electronic boards managed in units of a plurality of electronic boards will be considered next. Hereinafter, one production unit will be referred to as a batch. In a conventional case using a barcode or the like, if components A have run out during processing for a batch, and replacement of component reels for components A has occurred, information indicating that the component reel for components A has been replaced with another is managed as management information, but it is impossible to determine for which printed circuit board of the batch the replacing reel for components A has been used. In other words, lot management of components A to be used cannot be performed. Even if an RFIC (Radio Frequency Integrated Circuit) chip which is easier to individually manage than a barcode is mounted, since an ID can be generally read until after a reflow process, i.e., until the RFIC chip is soldered to a printed circuit board, it is impossible to determine the time of occurrence of replacement of reels for components A (replacement of lots) during processing for a batch, as in the case of a barcode.
When an RFID tag is attached to a printed circuit board in advance, if an ID in an RFIC can be read before a component mounting process (before the RFIC enters a chip mounter), component reel replacement histories can be managed on a per-printed-circuit-board basis. However, the position where a reader antenna is set needs to be adjusted according to the size of the printed circuit board and the position where the RFID tag is attached. If an RFID tag is affixed, poor silk screening may occur due to the thickness of the tag in a solder paste silk screening process. If an RFID tag is embedded in a printed circuit board, costs and the yield in an embedding process become issues.